Hybrid Engine Warm-Up Control for Emissions and Fuel Economy
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Solution Overview
Problem
Existing methods for reducing emissions in hybrid vehicles by limiting the load on the internal combustion engine during catalyst warm-up result in inefficient operation and poor fuel economy.
Innovation Solution
Implementing a warm-up control method that switches between emission-priority and fuel economy-priority modes based on engine temperature, using exhaust stroke injection and intake stroke injection to manage particulate matter and optimize fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the load on the internal combustion engine is limited during catalyst warm-up to reduce emissions, then particulate matter emissions are reduced, but fuel economy deteriorates
Solution Approach 1:
The patent applies dynamics by switching between two distinct warm-up control modes (emission-priority mode and fuel economy-priority mode) based on engine temperature conditions. The control system dynamically adjusts fuel injection timing and load limitations according to the current thermal state of the engine, transitioning from conservative emission control at low temperatures to more aggressive fuel economy optimization at higher temperatures.
Solution Approach 2:
The patent changes key operating parameters including fuel injection timing (switching between exhaust stroke injection and intake stroke injection) and load limitations based on engine temperature. By adjusting these parameters according to thermal conditions, the system optimizes the balance between emission control and fuel economy across different operating states.
2Object-generated harmful factors
If fuel injection timing is set to exhaust stroke injection to suppress particulate matter, then PN is reduced, but fuel economy deteriorates
Solution Approach 1:
The fuel injection timing is dynamically switched between exhaust stroke injection and intake stroke injection based on engine temperature. At low temperatures, exhaust stroke injection is used to minimize particulate matter formation. As the engine warms up, the system transitions to intake stroke injection which improves fuel economy while maintaining acceptable emission levels.
Solution Approach 2:
The injection timing parameter is changed according to engine temperature conditions. The control system adjusts the injection phase and duration to optimize the trade-off between particulate matter reduction and fuel consumption efficiency across different thermal states.
Data Source
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AI summary
A series hybrid vehicle is provided with an internal combustion engine (2) that drives a generator (1). The internal combustion engine (2) is operated in a catalyst warm-up mode after a cold start. When the cooling water temperature reaches a first temperature (TW1), the operation mode transitions to an emission-priority warm-up mode. In the emission-priority warm-up mode, the load is limited to a load lower than the best fuel economy point, and the injection timing is controlled so as not to overlap with an intake stroke. At a second temperature (TW2), the operation mode transitions to a fuel economy-priority warm-up mode, and operation is performed at a load that is the best fuel economy point. The injection timing is controlled such that an injection end timing is in the vicinity of the intake top dead center. When the cooling water temperature reaches a third temperature (TW3), the operation mode transitions to a normal operation mode.